“…This pathway is most sensitive to short or blue (460–480 nm) wavelengths of light (Berson et al., ; Czeisler et al., ; Reiter et al., ). Light at night can therefore disrupt circadian rhythms (Dominoni et al., ; Stevens & Zhu, ; Yadav, Verma, & Singh, ), which not only shifts the timing of the sleep–wake cycle, but also dampens its rhythm (Dijk & Archer, ; Fisher et al., ). Second, exposure to light can have direct effects on sleep and wakefulness, without necessarily affecting circadian rhythms (Altimus et al., ; Cajochen, Zeitzer, Czeisler, & Dijk, ; Chang, Scheer, Czeisler, & Aeschbach, ; Chen et al., ; Gandhi et al., ; Rattenborg, Obermeyer, Vacha, & Benca, ).…”